The effect of whole blood resuscitation on in-hospital mortality: A propensity score weighted analysis of patients treated at a Level I trauma center.

Background: Whole blood (WB) transfusion, compared with blood component therapy (CT), has been shown to have superior outcomes in the military population. However, whether this translates to the civilian population remains understudied. This study sought to determine the effect of WB on short-term in-hospital outcomes.

Methods: This retrospective cohort study included trauma patients at a Level I trauma center who received either WB or CT upon massive transfusion protocol activation between January 2021 and June 2023. The primary outcome was in-hospital mortality, and secondary outcomes included 24-hour mortality, 7-day mortality, 30-day mortality, trauma-induced coagulopathy, and the number of transfusion events required. The effect of transfusion type on patient outcomes was evaluated using a propensity-weighted modified Poisson regression.

Results: Of 1,027 massive transfusion protocol-activated patients, 480 (46.8%) received any WB. The propensity score weighting balanced the covariate distribution between the transfusion groups. Significant effect modification (p < 0.05) by injury type (blunt vs. penetrating) on mortality outcomes was observed. Compared with CT recipients, penetrating trauma patients who received WB had a significantly lower adjusted risk of in-hospital (risk ratio [RR], 0.36; 95% confidence interval [CI], 0.15-0.89), 7-day (RR, 0.37; 95% CI, 0.15-0.94), and 30-day (RR, 0.36; 95% CI, 0.15-0.89) mortality but not significantly different 24-hour mortality (RR, 0.39; 95% CI, 0.15-1.00; p = 0.05). An elevated risk of trauma-induced coagulopathy was observed among WB recipients than CT recipients with blunt trauma (RR, 1.59; 95% CI, 1.07-2.36) but not among patients with penetrating injury (RR, 0.65; 95% CI, 0.30-1.40). Compared with CT recipients, WB recipients had reduced transfusion rates for both penetrating (RR, 0.59; 95% CI, 0.36-0.95) and blunt-related injuries (RR, 0.73; 95% CI, 0.58-0.91).

Conclusion: The effect of WB on in-hospital mortality is modified by injury type, suggesting the need to consider penetrating injury as an important indication for WB resuscitation. In addition, WB reduces transfusion requirements across both injury types, decreasing patient exposure to transfusion events.

Level of evidence: Therapeutic; Level III.